+ Site Statistics
References:
54,258,434
Abstracts:
29,560,870
PMIDs:
28,072,757
+ Search Articles
+ Subscribe to Site Feeds
Most Shared
PDF Full Text
+ PDF Full Text
Request PDF Full Text
+ Follow Us
Follow on Facebook
Follow on Twitter
Follow on LinkedIn
+ Translate
+ Recently Requested

Light- and pH-dependent structural changes in the PsbS subunit of photosystem II



Light- and pH-dependent structural changes in the PsbS subunit of photosystem II



Proceedings of the National Academy of Sciences of the United States of America 100(25): 15265-15270



In higher plants, the PsbS subunit of photosystem II (PSII) plays a crucial role in pH- and xanthophyll-dependent nonphotochemical quenching of excess absorbed light energy, thus contributing to the defense mechanism against photoinhibition. We determined the amino acid sequence of Zea mays PsbS and produced an antibody that recognizes with high specificity a region of the protein located in the stroma-exposed loop between the second and third putative helices. By means of this antiserum, the thylakoid membranes of various higher plant species revealed the presence of a 42-kDa protein band, indicating the formation of a dimer of the 21-kDa PsbS protein. Crosslinking experiments and immunoblotting with other antisera seem to exclude the formation of a heterodimer with other PSII protein components. The PsbS monomer/dimer ratio in isolated thylakoid membranes was found to vary with luminal pH in a reversible manner, the monomer being the prevalent form at acidic and the dimer at alkaline pH. In intact chloroplasts and whole plants, dimer-to-monomer conversion is reversibly induced by light, known to cause luminal acidification. Sucrose-gradient centrifugation revealed a prevalent association of the PsbS monomer and dimer with light-harvesting complex and PSII core complexes, respectively. The finding of the existence of a light-induced change in the quaternary structure of the PsbS subunit may contribute to understanding the mechanism of PsbS action during nonphotochemical quenching.

(PDF emailed within 0-6 h: $19.90)

Accession: 004221986

Download citation: RISBibTeXText

PMID: 14657329

DOI: 10.1073/pnas.2533072100


Related references

Wheat truncated hemoglobin interacts with photosystem I PSK-I subunit and photosystem II subunit PsbS. Biologia Plantarum 57(2): 281-290, 2013

Photosystem II Subunit PsbS Is Involved in the Induction of LHCSR Protein-dependent Energy Dissipation in Chlamydomonas reinhardtii. Journal of Biological Chemistry 291(33): 17478-17487, 2017

Physiological functions of PsbS-dependent and PsbS-independent NPQ under naturally fluctuating light conditions. Plant and Cell Physiology 55(7): 1286-1295, 2015

Isolation of monomeric photosystem II that retains the subunit PsbS. Photosynthesis Research 118(3): 199-207, 2014

Structure-function analysis of photosystem II subunit S (PsbS) in vivo. Functional Plant Biology 29(10): 1131-1139, 2002

Biochemical properties of the PsbS subunit of photosystem II either purified from chloroplast or recombinant. Journal of Biological Chemistry 277(25): 22750-8, 2002

Interactions between the photosystem II subunit PsbS and xanthophylls studied in vivo and in vitro. Journal of Biological Chemistry 283(13): 8434-8445, 2007

PsbS-dependent enhancement of feedback de-excitation protects photosystem II from photoinhibition. Proceedings of the National Academy of Sciences of the United States of America 99(23): 15222-7, 2002

The PsbS protein plays important roles in photosystem II supercomplex remodeling under elevated light conditions. Journal of Plant Physiology 172: 33-41, 2015

Cosuppression of photosystem I subunit PSI-H in Arabidopsis thaliana. Efficient electron transfer and stability of photosystem I is dependent upon the PSI-H subunit. Journal of Biological Chemistry 274(16): 10784-9, 1999

Distinct roles of the photosystem II protein PsbS and zeaxanthin in the regulation of light harvesting in plants revealed by fluorescence lifetime snapshots. Proceedings of the National Academy of Sciences of the United States of America 111(49): 17498-17503, 2015

Molecular and global time-resolved analysis of a psbS gene dosage effect on pH- and xanthophyll cycle-dependent nonphotochemical quenching in photosystem II. Journal of Biological Chemistry 277(37): 33590-7, 2002

Subunit composition of Photosystem I complex that catalyzes light-dependent transfer of electrons from plastocyanin to ferredoxin. Journal of Biochemistry 110(4): 622-627, 1991

PHOTOSYSTEM II SUBUNIT R is required for efficient binding of LIGHT-HARVESTING COMPLEX STRESS-RELATED PROTEIN3 to photosystem II-light-harvesting supercomplexes in Chlamydomonas reinhardtii. Plant Physiology 167(4): 1566-1578, 2016

In Vivo Identification of Photosystem II Light Harvesting Complexes Interacting with PHOTOSYSTEM II SUBUNIT S. Plant Physiology 168(4): 1747-1761, 2016